The present invention relates to radio utility meter reading processing, and is more particularly but not exclusively concerned with a radio transmitter antenna arrangement which is associated with a utility meter, particularly a water meter, for the purpose of transmitting readings of such meter from a generally underground pit box to a remote receiver, and, in part, related methodology.
In conventional practice in the area of utility meter reading for data acquisition and automatic billing, a meter which is intended to be remotely read is installed with a radio transmitter. Such radio transmitter produces radio frequency energy that is coupled to an antenna for broadcasting.
Generally, the nature of such arrangements results in the antenna being placed in an outdoor environment, often at ground level, and in close proximity to a variety of materials and varying weather conditions. Nearby materials may include (and may change from time to time, depending on the environment) items such as metal, plastic, concrete, or organic materials. Weather conditions may involve, from time to time, environmental exposure to ice, snow, water, and temperature extremes (both cold and hot).
The amount of radio frequency energy actually irradiated into the airwaves as compared with that intended to be irradiated is a function of a number of factors. Such factors may include the applied voltage, the amount of current flowing through the antenna, the frequency of the signal applied to the antenna, the material from which the antenna is made, the geometry of such antenna, and the materials that are in a relatively close surrounding space of the antenna (such as within a sphere-radius measuring up to a few wavelengths of the radio signal applied to such antenna). When the surroundings of the antenna vary, the antenna performance (i.e., the degree of the radiated energy therefrom) will also tend to vary correspondingly. The more that adjacent or nearby materials tend to permeate the environment of a particular antenna, the greater the affects on the antenna and its performance, typically to the detriment of such performance.
As is well known, current flow is a function of applied voltage and the equivalent impedance of the system. The equivalent impedance system for an antenna generally is a function of the efficiency of the antenna itself, of the impedance characteristics of the transmission line which is carrying the radio frequency energy from a transmitter to such antenna, and of the geometry of such antenna that presents a particular impedance at given frequencies of operation.
To achieve desired range and reliability of radio frequency communications from pit box generated data, it would be desirable to maintain a controlled and also uniform radio frequency energy irradiation pattern from the antenna used to transmit a radio signal from an enclosed utility meter. One type of antenna conventionally used for utility meter remote transmitting uses a conventional loop antenna design as the irradiator element. Generally speaking, the proximity to the ground which is required for the arrangement results in a deformation in the irradiation pattern produced by the irradiated signal.
Problems encountered with such non-uniform irradiation patterns are further complicated by the fact that irradiated energy may vary from place to place where the antenna is installed. For example, in some antenna systems there may be multiple transmitters that will be sending data to a receiver system, where the transmitter antenna will be installed in cast iron, plastic, or concrete lids of boxes installed underground and with lids thereof generally flush with ground level. Such boxes are commonly called pit boxes in the utility industry, particularly in the water utility industry.
A number of attempts have been made to provide an antenna system that is capable of operating in particular from a water meter pit box environment. However, complete systems for water meters on occasion have been required to be removed from the field for reasons such as poor antenna function, poor range, inconsistent range, and other related problems that also affect the life and/or durability of the effective water meter reading system using a radio frequency transmitter system for data collection.
A number of factors are subject to consideration in providing any successful integrated antenna system. A few of such conditions or factors may include: frequency of operation, transmitter output power, antenna gain, antenna polarization, antenna pattern, azimuth beam-width, azimuth variation, government regulations for operating radio equipment, characteristic antenna impedance, coefficient of maximum wave reflection, antenna geometry, antenna location, ability to effect installation, length of service life desired, ability to operate in exposed environmental conditions such as exposure to water with only very small variation in operation performance due to any water absorption into the antenna system, ultra-violet resistance, shock and vibration resistance, and environmental temperature variability resistance. At the same time, one must be aware of cost factors and the ability to manufacture a large volume of such units (for use in a full system having a number of meter reading locations) with reliability and repeatability of performance.
Examples of several known antenna arrangements for use with utility meter pit boxes are disclosed in Cerny, et al. (U.S. Pat. No. 5,298,894) and Meek, et al. (U.S. Pat. No. 5,621,419). The complete disclosures of such patents are fully incorporated herein by reference.
The present invention recognizes and addresses various of the foregoing problems, and others, concerning pit box antenna arrangements. Thus, broadly speaking, a principal object of this invention is improved pit box antenna arrangements. More particularly, a main concern is providing improved antenna arrangements for desired quality of utility meter communications even if antenna elements are at least partly exposed to their surrounding environment.
It is another general object of the present invention to provide improved pit box antenna arrangements which have improved range and reliability while still providing an arrangement which may reside close to the ground, for example, to accommodate mowing.
A more particular object is to provide an improved pit box antenna arrangement which functions in conjunction with a pit lid opening, so as to have an antenna element portion at least partly situated above an exterior, above ground portion of the pit box lid for propagating utility meter data from a utility meter within the pit box to a remote utility meter data collection unit.
It is a further more particular object of the present invention to provide such improved antenna arrangements which are operable generally with a variety of utility meter types, such as gas, electric, and water utility meters. It is an additional such object to provide an improved antenna arrangement which may be used in a variety of settings, in conjunction with various transmitters which might be associated with the output of a given utility meter in a given embodiment of a pit box arrangement.
Yet another general object of the present invention is to provide an improved pit box antenna arrangement such that transmitter and antenna features may be coupled together without requiring mechanical coupling. In other words, for example, use of capacitive coupling between transmitter and antenna elements is a specific object for providing improved apparatus and methodology.
Still more particular objects of the present invention relate to providing various components of improved pit box antenna arrangements which may be nestably received with respect to each other. It is a more specific object to provide such components for both improved apparatus and methodology, for improved efficiency during installation and maintenance relative to installing and/or removing such arrangements or parts thereof relative to pit box lids of the type having an opening therethrough.
Yet another more particular object of the present invention is to provide an improved pit box antenna arrangement for use in conjunction with a pit lid opening, such that the top of a radiating antenna element is larger than the opening in the pit lid, to permit such improved arrangement to withstand relatively higher impact loads.
Still another object of the present invention is to provide sealable ends of connections between antenna and transmitter components, for preventing damage to either component from environmental or weather conditions, even when such two components are separated or kept separate through capacitive coupling.
Additional objects of the present invention may be obtained by providing improved pit box antenna arrangements such that the ground plane of the antenna may be external, for allowing a metal pit lid to become an extension of such ground plane. Further objects are obtained by enabling the upper or top radiator element of such improved antenna arrangement to be made of various shapes without adversely affecting radiation of the antenna, such as a curved shape for shedding water.
Additional objects and advantages of the invention are set forth in, or will be apparent to those of ordinary skill in the art from, the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated and disclosed features, materials, devices or steps hereof may be practiced in various embodiments and uses of this invention without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitution of equivalent means, features, materials or steps for those shown or discussed, and the functional or positional reversal of various parts, features, steps or the like.
Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this invention may include various combinations or configurations of presently disclosed features, elements or steps or their equivalents (including combinations of features or steps or configurations thereof not expressly shown in the figures or stated in the detailed description). One exemplary such embodiment of the present invention relates to radio frequency utility meter communication apparatus for transmitting utility meter data to a remote utility meter data collection unit from an underground pit box receiving a utility meter and having a generally ground level pit lid with an opening therethrough.
The foregoing exemplary embodiment of communication apparatus may comprise an antenna element, an RF transmitter, and utility meter interconnection means, all in accordance with the subject invention.
The foregoing exemplary antenna element may have a top cap larger than the pit lid opening and received thereabove. It may further have a depending base extending from such top cap and passing through the pit lid opening into the underground pit box.
The foregoing exemplary RF transmitter may be situated inside the underground pit box and electrically coupled with the antenna element depending base without mechanical connection thereto such that RF signals transmitted by such RF transmitter are propagated by the antenna element. The exemplary utility meter interconnection means are provided for interconnecting data from a utility meter within such underground pit box to the RF transmitter also situated therein.
With the foregoing exemplary arrangement, the antenna element top cap, at least partly situated above an exterior, above ground portion of the pit lid box, propagates utility meter data from the utility meter within the pit box to a remote utility meter data collection unit.
Another present exemplary embodiment concerns an arrangement for obtaining data from a utility meter received in an underground pit box of the type having a lid with a predetermined opening therethrough. Such arrangement preferably comprises transmitter means combined with antenna means, in accordance with the subject invention.
The foregoing exemplary transmitter means are received within such a pit box and interconnected with a utility meter received therein for transmitting utility meter data therefrom. The exemplary such antenna means are preferably capacitively coupled with such transmitter means so as to receive output therefrom without requiring mechanical connection, and extend at least partly through such pit lid predetermined opening. With such an arrangement, the utility meter data advantageously transmitted by such transmitter means are propagated by the antenna means.
In the foregoing exemplary arrangement, such antenna means may alternatively include an upper generally circular member or top cap passed through (i.e., residing above) the predetermined opening of the pit box lid and generally larger than such pit lid opening. It may further include a lower generally straight member (or depending base) extending downwardly from such upper member or top cap so as to extend and pass through the pit box lid opening down into the pit box. In such an arrangement, the antenna means may become at least partly exposed to its surrounding environment.
Further alternatively, in the foregoing exemplary arrangement, part of such antenna means extending through the pit lid predetermined opening may be protectively covered by electromagnetically transparent materials. In still further alternative arrangements of such exemplary embodiment, such antenna means may be directly coupled with a metallic pit lid with which the arrangement is associated so that such metallic pit lid functions as part of the antenna for such transmitter means.
Yet another present exemplary embodiment concerns a radio frequency utility meter communication apparatus for transmitting utility meter data to a remote utility meter data collection unit from an underground pit box receiving a utility meter and having a generally ground level pit lid with an opening therethrough, such communication apparatus comprising in combination a particular antenna element, antenna securement means, an RF transmitter, and utility meter interconnection means, all in accordance with the subject invention.
In the foregoing exemplary embodiment, such antenna element preferably has a top cap larger than the pit lid opening and received thereabove, and has a depending base extending from such top cap and passing through the pit lid opening into the underground pit box.
The foregoing exemplary antenna securement means are preferably provided for securing such antenna element in a fixed position relative to an associated pit lid with such top cap of the antenna element received above the pit lid opening and with the depending base thereof extending through such pit lid opening.
The foregoing exemplary RF transmitter is preferably situated inside the underground pit box and associated with such antenna element depending base such that RF signals transmitted by the RF transmitter are propagated by the antenna element. The exemplary utility meter interconnection means are provided for interconnecting data from a utility meter within an underground pit box to the RF transmitter situated inside such underground pit box. With such an arrangement, the antenna element top cap, at least partially situated above an exterior, above ground portion of the pit box lid, propagates utility meter data from the utility meter within the pit box to a remote utility meter data collection unit.
In a further exemplary embodiment, alternatively, such foregoing exemplary top cap may comprise a separate component joined with a ground plane component forming an upper portion of such depending base. In such exemplary alternative arrangement, the antenna securement means preferably includes radially outward threads carried on an outside diameter portion on the antenna element depending base.
In still another present exemplary embodiment, an arrangement is provided for obtaining data from a utility meter received in an underground pit box of the type having a lid with a predetermined opening therethrough, such arrangement comprising transmitter means and antenna means in accordance with the subject invention.
The foregoing exemplary transmitter means are preferably received within such pit box and interconnected with a utility meter received therein for transmitting utility meter data therefrom. The exemplary foregoing antenna means are preferably electrically coupled with such transmitter means so as to receive output therefrom without requiring mechanical connection thereto. Such antenna means extend at least partly through such pit lid predetermined opening so as to be outside such pit box and at least partly electromagnetically thereabove. With such an arrangement, the utility meter data transmitted by such transmitter means are propagated by the antenna means from outside and above such pit box.
Another present exemplary embodiment concerns an arrangement for obtaining data from a utility meter received in an underground pit box of the type having a lid with a predetermined opening therethrough, such arrangement comprising a particular combination of transmitter means, antenna means, and reversible installation means in accordance with the subject invention.
The foregoing exemplary transmitter means are received within such pit box and interconnected with a utility meter received therein for transmitting utility meter data therefrom. The foregoing exemplary antenna means are preferably associated with such transmitter means and extend at least partly through such pit lid predetermined opening, so that utility meter data transmitted by the transmitter means are propagated by the antenna means.
The foregoing exemplary reversible installation means are provided for removably securing such antenna means relative to the associated pit lid and for removably securing the transmitter means relative to the above-referenced antenna means. With such an arrangement, a data transmission arrangement is removably installed within a utility meter pit box relying only on the pit box lid as a base of support.
In yet another exemplary radio frequency utility meter communication apparatus, an apparatus is provided for transmitting utility meter data to a remote utility meter data collection unit from an underground pit box receiving a utility meter and having a generally ground level pit lid with an opening therethrough. Such communication apparatus comprises an antenna element, an RF transmitter, and utility meter interconnection means in accordance with the subject invention.
Such antenna element preferably has a top cap larger than the pit lid opening and received thereabove. It may further have a depending base extending from such top cap and passing through the pit lid opening into the underground pit box.
The exemplary RF transmitter is situated inside the underground pit box and associated with such antenna element depending base such that RF signals transmitted by the RF transmitter are propagated by the antenna element. Such utility meter interconnection means are provided for interconnecting data from a utility meter within an underground pit box to such RF transmitter situated inside the underground pit box.
With the foregoing exemplary arrangement, the antenna element top cap, at least partly situated above an exterior, above ground portion of the pit box lid, propagates utility meter data from the utility meter within the pit box to a remote utility meter data collection unit.
Lastly, further embodiments of the subject invention preferably relate to corresponding improved pit lid antenna nested mounting arrangements and corresponding methodology for the practice of same. Such nested mounting arrangement preferably provides improved radio transmission of utility meter data from an underground pit box of the type having a removable generally ground level pit lid with a predetermined opening therethrough.
Such exemplary nested mounting arrangement includes a generally elongated antenna element, an antenna main body nesting component, a capture nut, a transmitter housing, and utility meter interconnection means as before.
The foregoing exemplary elongated antenna element is preferably formed so as to reside with a head portion thereof at least partly through an associated pit lid opening and with the remainder thereof depending downwardly into the associated pit box.
The antenna main body nesting component may comprise an elongated generally cylindrical and hollow tubular piece with a relatively enlarged head end corresponding with the antenna element head portion for nesting receipt thereof. Such main body nesting component further defines outside diameter threads, and at least one matable engagement element at an end thereof distal to such head end thereof.
Further provided is a capture nut which is fittable around such threaded outside diameter of the main body nesting component for drawing tight against an underside surface of the associated pit box lid as the relatively enlarged head end of such main body nesting component and as the antenna head portion are caught and drawn tight on the outside of the pit lid through the opening thereof.
The foregoing exemplary transmitter housing is received within the pit box and with a battery operated radio transmitter enclosed therein. Such housing preferably has an antenna coupling post with an open end for telescopically receiving the antenna element depending portion therein capacitively coupled thereto without direct physical contact. Such housing antenna coupling post further has an external matable engagement element adjacent a base portion thereof, complementary to the antenna main body nesting component matable engagement element for selectively locking such antenna coupling post and the transmitter housing to the main body nesting component.
Exemplary embodiments of the present invention include corresponding methodologies for removably installing such a nested pit lid antenna mounting arrangement, wherein the capture nut is selectively fitted around the threaded outside diameter of the main body nesting component for drawing such nut tight against an underside surface of the associated pit box lid, and wherein the antenna coupling post is selectively locked with the transmitter housing to the main body nesting component using the indicated respective engagement elements.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the remainder of the specification.